Allow building std with cranelift

- Don't pass llvm-specific args when using cranelift
- Don't use `asm` in compiler_builtins when using cranelift

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -567,7 +567,7 @@ fn codegen_msvc_try<'ll>(
         // module.
         //
         // When modifying, make sure that the type_name string exactly matches
-        // the one used in src/libpanic_unwind/seh.rs.
+        // the one used in library/panic_unwind/src/seh.rs.
         let type_info_vtable = bx.declare_global("??_7type_info@@6B@", bx.type_i8p());
         let type_name = bx.const_bytes(b"rust_panic\0");
         let type_info =